Air collector for propellers



July 19, 1932.

T. A mcKs" AIR COLLECTOR FOR PR PELLERS Filed April 25; 1931 5 Sheets-Sheet 1 E 4 INVENTOVR 11M a 0% '4a' a; 3 7m July 19, 1932. 'r. A. DICKS I AIR COLLECTPR FOR PROPELLERS Filed April 23, 1931 SShGBtS-ShGQt 3 INVENTOR July 19,1932. T. A. DICKS AIR COLLECTOR FOR PROPELLERS 5 Sheets-Sheet 4 Filed April 23, 1931 7 July 19, 1932. v T. A. DlcKs AIR COLLECTOR FOR' PROPELLERS Filed April 25, 19:51 5 Sheets-Sheep 5 INVEQT'OR ,3 www Patented July 19, 1 932 UNITED STATES PATENT or F'IC'E f THOMAS A. IJIQKS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO PITTSBURGH SCREW & BOLT CORPORATION, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION 01' PENN- SYLVANIA Application filed April 28,

This invention relates to airplane propellers, and in particular to a device for collect ing and directing air through the hub of the thereof. In my pending application, Serial designed to .overcome this deafenin No. 499,511, filed December 2, 1930, I disclosed one type of propeller constructed and noise and also to increase the efliciency oft e propeller in which air is drawn throu h ports in the hub and is discharged along t e trailing edge of the blade. In that application I relied upon the Venturi effect set up in the blade by air passing across openings on the trailing edge thereof and also on centrifugal force, to draw the air through the hub into the blade. p

It'is an object of the present invention to provide an air collector for positively forcing air through the blade of a propeller to neutralize the vacuum formed alon ing edge of the blade so as to ecrease the noise and materially increase the efliciency of the ropeller.

Anot er object of this invention is to provide an air-collector which may be applied to an type of propeller hub.

v A urther object of this invention is to provide an air collector for forcing air into the hollow blades of an airplane propeller which is relatively simple in constructlon, relatively cheap to manufacture and readily applled to the propeller.

These and other objects which will be made apparent to those skilled in thisparticular art are accomplished by means of this invention, one embodiment of which is described in the following specification and illustrated in the accompanying drawings, wherein; a 1 4 Figure 1 is a view in front elevation of a the trail AIR coLLnc'roa ron PROPELLERB 1931. Serial No. 532,201.

propeller hub having an air collector secured thereto.

Fig. 2 is a view on line IIII of igure 1'.

' Fig. 3 is a view in III--III of Fig. 2.,

Fig. 4 is a v ew in perspective of the hub and air collector shown in Figure 1.

Fig. 5 is a view in frontelevation of a propeller hub and an air collector showing. a modification of my invention. 1'

Fig. 6 is a viewin side elevation of the hub shown in Figure 5 having a portion thereof broken away for convenience ofillustration.

Fig. 7 is a view in section taken on line VII-VII of Fig. 6.

section taken on line Gil Fig. 8 is a view in perspective of the hub v and air collector shown in Figure 5.

Fig. 9 is a view in front elevation of a propeller hub and air collector. embodying another modification of my invention, and

Fig. 10 is a'view in side. elevation of the hub shown in Figure 9 having a portion thereof broken away for clearness in illustration.

In the several'figures of the drawings, like characters refer to like portions of the structure.

Referring now to Figures 1, 2, 3, and 4 of the drawings in detail, 10 designates a hub provided with a transverse axial sleeve 11 in which the drive shaft is adapted to be secured in any appropriate or well known manner. Integrally formed on the hub portion 10 are annular sockets 12, each of which is provided with relatively thickened ortions 13, adjacent the hub portion throug which a bolt 14 of the usual type extends for fastening the shank of a blade 15 in the socket.

The sockets are also provided with clamping lugs 16 on the outer ends thereof through securely around the end of the bolt. The shank 15 of the blade is provided with a notched ortion 17 which registers with a port 18 ormed in the wall ofeach of the sockets 12. The ports 18 are formed on the leading face of the sockets-12, that is, the ports face in they direction of rotation of the which bolts extend forclamping the socket hub and not the direction of travel of the plane. I a When the propeller is whirling at a high rate of speed, air is drawn into the blade through the registering ports 17 and 18 and is discharged into the partial vacuum formed along the trailing edge through slots formed along the trailing edge of the blade (not shown). The air drawn through the ports 18 in the sockets 12 tends to neutralize the vacuum and decrease the noise of the whirl in of the propeller.

that air will be positivelp through the ports into the blades, provide an air collector or rin which directs the air through the ports 1 and 18 and forces the same into the bladewhere it is discharged along the trailing ed e; The air collector comprises a cup-shape member 20 which is secured to the sockets of the hub and which faces in the direction of travel of the plane so that the member will collect air when the plane is in motion and force the same into' the blades through the ports 17 and 18. 1

The walls of the cup-shaped member 20 are cut awa at 21 for receiving and partially enclosing the sockets 12 when the air collector or ring is secured to the hub. The

base 22 of the bottom of the cup-shaped 'member 21 is of channel shape, as shown in Figure 3, for receiving the thickened portions 13 formed on the sockets 12. The base is also shown) t hub. It is apparent that such a construction permits the collector to fit snugl against the hub and sockets 12 so as to orm pockets the - of rotation o for collecting the air on each side of the hub adjacent the ports 18. The cup-shaped member 20 is' secured to the sockets by the bolts 14 which extend through openings formed in the base 22 of the member.

In Figures 5, 6, 7, and 8, I have illustrated a hub construction which differs from the construction of the hub heretofore explained in that the bolts 14 which secure the blades 15 in the sockets 12 extend through the sockets at right angles to the axial sleeve 11, while orts 18' which are formed in the walls of t e sockets 12, face in the direction of travel of the fplane and not in the directio the propeller. The air collector or ring for directing and forcing air through the ports 18' in this modification, comprises an annular base member. 30 having a wall portion 31 formed around the periphery which collects and" holds the air on the base member. In order that the air collector may fit snugly against the hub, the base 30 is provided with a trough 32 of the'same contour as themnul'ar sockets 12 which receives the sockets when the air collector is positioned on the forced provided with an opening (not rough which the sleeve 11 extends when the air collector is positioned on the hub.. The trough 32 .extends diametrically on the base and is provided with a series of openings, one of which receives the. front end of the hub portion 10 while the other openings, designated as 33, register with the ports 18' in the sockets 12. The air collector is held in position on the front end of the hub by the bolts 14 which extend through openings formed in legs 34 depending from the base member on the opposite sides of; the trough 31. When the plane is in motion. air .is collected in the base member 30 by" the walls 31 which extend outwardly from the base member in the direction of travel and is forced by the oncoming'air through the ports 33,18 and 17 into the blades where it is exhausted along the trailing edge.

1 In Figures 9 and 10 I have illustrated another modification of m invention in which .an air collector is app ied to an assembled ally extending sockets 44 which receive shanks 45 of. the propeller blades. The blades are retained inthe sockets by shoulders 46 extending inwardly from the inner face of the sockets 44 which engage shoulders 47. formed on the shanks 45 of the 5 blades. A clampin ring 48 positioned around the outer en of each of the sockets 44 securely lock the blades to the hub.

Each of the sockets is provided with an opening-49 adjacent the base thereof which faces in the direction of travel of the Plane and which registers with an opening 50 formed in the shank 44.0f the blade. The

outer ends of the blade used in this modi- I fication, as in the revious modifications having slots forme along 1 the trailing edge lector is positioned on the hub. The air collected on the annular portion 51 is forced through openings 54 which are formed in the troug 'and registers with the openings 49 1n the sockets. The collector is held on the hub by the bolts 42 which extend through .a centrally located thickened portion. 55

formed on the base portion 51.

. From the foregom description, it is read- 11y apparent that I ave desi 'ed a device w ich collects and positively orces air into the blades where it is exhausted along the trailingedge of'the blade, neutralizing the no vacuum, and consequently decreasing c'onsiderablythe noise of the propeller, andin- I creasing the efliciency of the propeller.

It is to be understood that the invention is not limited to the constructions herein specifically illustrated but can be embodied in other forms without departing from the spirit of the invention or the scope of the appended claims.

What-I claim as new and desire to secure by Letters Patent is:

1. In a propeller, the combination with a hub having a series of annular blade receiving sockets extending radially therefrom, of a member secured to said sockets havin an annular wall extending beyond said hu so as to direct air into said propeller throu registering openings in said member and said sockets.

2. The combination with a propeller hub, havin a series of radially disposed sockets exten ing from said hub each having a port therein, of a member secured to said hub having curved wall portions thereon extending around said sockets was to form pockets adrecting it through the orts.

3. An air collector orforcing air into a propeller hub having radially disposed blade receivin sockets provided-with ports on the leading acethereof, com risingacup-shaped member secured to said ub, and having the walls thereof extending around said sockets so as to form air pockets adjacent the ports therein.

4. An air collector for forcing air into an airplane pro eller hub having a series of radially extending sockets, each of which is provided with a ort facing in the direction of rotation of said hub, com rising a cup-shaped member secured to said ub and having portions of the wall thereof cut away for receiving said sockets and forming pockets ad]acent the ports therein.

5. An air collector for forcing air through an airplane propeller having openings along the trailing edge and a hub portion provided with radially extending sockets each of which has an opening therein and facing in the direction of travel of the plane, comprising an annular member havin through for receivin said sockets, and pro vided with ports registerin with the ports in said sockets, and means or collecting the air on said member and directing it into said ports.

6. .An air collector for forcing air through an airplane propeller having a hub portion provided with radially extending sockets each of which has an opening therein facing in the direction of travel of the plane and a propeller blade for each socket provided with a port registerin with the port in the socket and an opening a ong the trailing edge, comprising an annular member having ports reg- 1 extendin acent said ports for collecting air and di-v a trough thereistering with theports in said sockets a wall from the periphery of said member formmg a pocket for receiving air and 7 directing it through said ports, and means depending from said member for securingthe member to said sockets. I

' 7 An air collector for forcing air through an airplane propeller having openings along the trailing edge and a hub portion provided with radially extending sockets each of which has an openingtherein facing in the direction of travel of the plane, comprising a member having a trough formed therein, said trough having a plurality of openings therein for receiving the end of said hub and registering with the ports in said sockets, a wall extending from the periphery of saidmemher for collecting air on said member and directing it through said ports, and means for securing said member to said hub.

8. An air'collector for forcing air through an airplane propeller having a series of openmgs along the trailing edge and 'a hub ortion provided with radially extending sockets each of which has an opening therein, facing in the direction of travel of the plane,icomprising a member having a series of openin therein, for receiving the end of said hub and i for registering with the ports in said sockets, a wall extending from said member for collecting air therein and directing it through said ports, legs depending from said member, and means extending through said legs for securing said member to said hu 9. An air collector for forcing air into an airplane hub having radially extending sockets extending therefrom, each of which is provided with an opening through the wall thereof. comprising a member having a series of openings therein, one of which is ada ted to receive the end of said hub while the ot ers register with the openings in said sockets, means for collecting air on said member, and means for securing said member to said hub.

10. An air collector for forcing air into an airplane hub having radially extendin I sockets extending therefrom, each of whic isprovided with an opening through the wall thereof, comprising a member having a hubreceiving portion formed therewith, troughs in said member for receiving the sockets and having openings therein registering with the openings in the sockets, a wall around the periphery of said member for collecting air on said member, and means extending throu h the hub-receiving portion for securing said member to said hub.

11. In a propeller, in combination, a hub, radially disposed sockets extending from said hub, each of which has a port. formed therein, a hollow propeller blade for each of said sockets havinga ort in the shank thereof registering witht e port in said socket and a series of slots along the trailing edge thereof, and a'member secured to said hub for collecting air therein and directin it through the registering ports into said b ade where it is exhausted through the slots along' the trailing edge thereof. .1 r

12. In an airplane propeller, in combination, a hub, radially disposed sockets extending from said hub, each of which has a port formed therein, a hollow propeller blade for each of said sockets having a port in the ports in said soc ets for collecting air therein I shank thereof registering with the port in said socket and a series of slots along the trailing edge thereof, a membersecured to said hub havin ports registering with the and forci'ngit through said blades and exhausting it along the trailing edges thereof.

13. In a propeller, in combination, a hub, a series of raidally disposed sockets extending from said hub each having a port formed therein, a hollow propeller blade for each of a said sockets having a port in the shank thereof registering with the port in said socket and a series of slots along the trailing edge there of, and a cup-shaped air collector securedto the hub for directing air through the registering ports into said blades and causing it to be discharged along the trailing edges,

14. In a propeller, in combination, a hub, a

series of-radially disposed sockets extending from said hub, each having a port formed therein, av hollow propeller blade'for each of said Sockets having a port in the shank thereof registering with the port in said socket and slots alongthe trailing edge, and a cup-shaped member having the base thereof a secured to said hub and having ports registering with the ports in said sockets for forcing air into said blades and discharging it along the trailing edges of the propeller.

15. In a propeller, in combination, a hub. havi g a series of radially extendin sockets, each of which has a port formed t erein, a-

hollow propeller blade for each of said sockets=hav1ng a port registering with the port in said socket and having a series of slots along the trailing edge thereof, and means secured to said hub for positively forcin air into said blades and through'the slots al .the trailing ed es of the blades to decrease the noise 0 sai ropeller.

16. In a prope ler, in combination, a hub having a series of radiall extending sockets,

each of which is provide witha port on the leading faces thereof, a hollow propellerblade for .each of said sockets having a port fegistering with the port in said socket and havingslotsalong the trailing edges thereof,

' r and a member secured to said hub and turrounding said sockets forming pockets for collecting air and directing it through said blades. 7

In testimony'whereof I have hereunto subscribed my name this 22nd day of April,

- THOMAS A. DIGKS.

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